Film gate



fiept. 9, 1941. s. a. @mmsom 2,255,638

FILM GATE Original Filed April 21, 1959 I/v VEN TOR. I Samuel 8. Graham SQQJ QQQL His Afforncys.

is shown at 2!.

Patented Sept. 9, 1941 FILM GATE Samuel B. Grimson, New York. N. Y., assignor to Color Research Corporation, New York, N. Y., a corporation of Delaware Original application April 21, 1939, Serial No.

Divided and this application March 14, 1940, Serial No. 323,886

2 Claims.

This invention relates to a film gate structure for use in printing colored photographs, including motion pictures.

' The general object of this invention is to provide a novel film gate combination including a diffraction grating and mechanism for positioning the diffraction grating axially, circumferentially, and transversely or radially in order to adapt it for use in a novel method of printing colored pictures.

This invention resides substantially in the combination, construction, arrangement, and

relative location of parts, as hereinafter more fully explained.

This application is a division of my copending application Serial No. 269,068, filed April 21, 1939, for Color photography.

Figure 1 is a vertical, central, cross-sectional view of the novel unitary structure comprising the film gate, the diffraction grating, and the adjusting mechanism therefor of this invention;

Figure 2 is a rear elevationalview thereof.

In some respects the subject matter herein disclosed is related to the subject matter of my copending application Serial No. 176,440, filed November 26, 1937, for Diffraction method and apparatus for color photography, now Patent Referring to Figures 1 and 2, there is illustrated a film gate of the well known Bell-Howell type, showing the mechanism 22 for moving the film on and off the registration pins and pulling it down. The film guide and pressure plate The plate 20 is removably mounted on a suitable support l9. Mounted on the plate 20 is a plate 23, having an opening in which lies concentrically therewith a disc 24 having a central opening. The disc 24 is mounted for circumferential'rotation by means of a worm 25 engaging teeth 21 on the periphery thereof. The worm is Journaled in the plate 23 and is rotated by means of a thumb screw 25. The disc 24 is held in the opening of plate 23 by means of a ring 30 secured thereto by means of the screws 3i and cooperating with a corresponding ring 32 secured to the plate 23 by means of the screws 33. Thus the disc 24 may be given circumferential movement to the desired degree while it is held strictly in a plane parallel to the gate aperture. Secured to the top of plate 20 is a journal 28 for a vertical thumb screw 29 which is connected to the plate 23. The plate 23 is mounted in vertical guides formed by the bars 33 attached to the sides of plate 23. Thus by be given vertical movement, carrying with it the parts attached thereto, including the disc 24.

The tubular member 34, internally threaded, is provided with a flange which fits under a flange on the ring 30 so that the tubular member may be rotated. At 35 are a pair of pins mounted on the disc 24. Slidably mounted on the pins 35 is a casing 31 having an externally threaded flange, the threads of which engage the internal threads of the tubular member 34. The inner end of the casing 31 has mounted therein a diifraction grating 36 of the type known as a filled grating. As is well known in the art, the filled grating consists of a series of parallel lines extending across one surface of an optically fiat piece of glass made by ruling them thereon and filling them in so that the filled ruled lines are rendered opaque and are separated by clear lines which are preferably, but not necessarily, onethird as wide as the ruled or opaque lines.

With this arrangement it will be seen that the diffraction grating can be very accurately positioned with respect to the film gate. It can be moved up and down, as previously described, with the thumb screw 29. It may be rotated in a vertical plane by means of the thumb screw 23 so that the horizontally ruled lines thereon may be placed exactly parallel in a horizontal direction with the lines on the black and white positive F2 registered in the film gate 2 I. The image structure of color separation film composed of linear densities is described in more detail in the said patent mentioned below. The diffraction grating may be adjusted in a direction at right angles to the plane of the film by rotating the tubular member 34. As this is rotated the casing 31 slides on the pins 33 so that the grating, the ruled surface of which is adjacent to the film F2, may be exactly positioned to give the overlapping focus described in connection with taking in the above mentioned Patent No. 2,164,062. It is of importance, of course, that in printing the difiraction grating have the lines thereof exactly parallel with the linear densities on the film F2 and be plane-parallel with the film.

It will be apparent from the above description that the novel features of this invention are subiect to wide variation without departure from the scope of the novel subject matter herein disclosed. I do not, therefore, desire to be strictly limited to the disclosure as given for purposes of illustration, but rather to the scope of the claims granted me.

What I claim is:

means of the thumb screw 29 the plate 23 may 1, A m gate mechanism for use in photo,

processes employing a e color semen eee densiefies, meme: m e member he an epeeture herein, memes positioned adjacent said apex-maze ion mfiemflm @emtly moving such film therep-esfi; and for holdsing it at said eeerture during its periofis of rest, a filled dim-action grating, a, support for said grating for it close to said aperture and pemllei thereiso, means for veryms the posiisflm oi mid grating sueport alone on axkefi line at angies fio the meme of we esp-22mm so me the gmfiing may be apeoee'i in desired per 7 eeee eee respect tome linear densities on the when at zest in said epemu'e,

2. A gefie sfizmcture oi the type described inelu a support having an amzmlre therein, eons for intermittently moving 2, film in the direotion of its length past said epex'ture, means for Eeolfilng the fiet e2", said aperture when at rest, e led difiractiom grefimg positioned eloee $0 said aperture and penile thereto, a, supporting structure 0? said grating, means for emusfing said supporting structure towards endewey from the aperture while maintaining it pamllel thereto, means 202* zoteemonelly adjustwe said supporting stmctuxe about an we:

line at right angles to the meme oi said aperture,

and m for vertically positioning the support. ing structure with respect to seid aperture.

u. 1 1m B. GRIMSON. 

